声品质排气消声器的正向设计方法

摘要

为提升某乘用车急加速工况下排气噪声的运动感,通过控制排气噪声主要阶次声压级和能量配比从而达到改善排气声品质的目标.从典型消声器结构单元消声频率与阶次对应关系入手,推导典型消声单元传递损失与排气噪声的阶次相关性;基于某乘用车排气系统消声器模型设计四组正交组合方案,采用CAE方法研究抗性消声器结构对阶次噪声的影响规律,总结出排气噪声中四阶成分与六阶成分对扩张腔结构参数、四阶成分对共振腔结构参数、二阶成分对赫尔姆兹谐振腔结构参数变化敏感的规律.以此为依据正向设计消声器,实现排气噪声阶次成分调整.加工样件并进行排气噪声尾管试验,证明排气噪声阶次成分分布满足设计要求,主观感受声品质满足运动感目标.该研究可为消声器正向开发及声品质目标实现提供借鉴.%In order to improve the sound quality of the exhaust noise of passenger cars in urgent acceleration condition, the main stage sound pressure level and energy ratio of the exhaust noise is controlled. According to the relationship between the frequency and the order of the muffler in the typical exhaust system, the correlation between the transmission loss and the order of the exhaust noise is derived. Based on the muffler model of the exhaust system of a passenger car, four groups of orthogonal combination schemes are designed. Using the CAE method, the impact of the resistance muffler structure on the order noise distribution is explored. It is summarized that the fourth order component and the sixth order component are sensitive to the expansion cavity structure parameters;the fourth order component is sensitive to the resonant cavity structure parameters; and the second order component is sensitive to the Helmholtz harmonic cavity structure parameters. On this basis, the muffler is designed. The order adjustment of components distribution of the exhaust noise is realized. Samples of the muffler are processed and tested and the exhaust tailpipe noise is measured. Results of the testing show that the order component distribution of the exhaust noise can meet the design requirements and the subjective perception of sound quality can meet the target of acceleration. The research has provided a reference for top-down development of mufflers and the realization of the target of sound quality.